20 December 2018


Many years ago, inspired by flocking algorithms, I made a Flash game based on the Border Reivers. Try it now on your desktop, before Flash finally dies for ever.

Ancient history: computer animation in the 1980s

In the 1980s, I saw a long documentary on computer animation on Channel4. It included many of the early Pixar short films (Luxo Jr, Tin Toy, Knick Knack) together with extensive interviews with John Lasseter.

It also included a short section which described animating flocks of birds. This was based on the work of Craig Reynolds. The theory is that, while the motion of a flock of birds is fantastically complex, a bird’s brain is not. A bird must therefore follow a few fairly simple rules in order to fly in a flock.

If one could approximate these rules mathematically, one could build a group of objects in a computer animation, and program them to follow these rules. The idea of emergent phenomena realistically modelling nature fascinated me.

Reynolds managed to formulate extremely simple rules, and coded them, animating what he called boids — objects in a procedural computer animation which follow their own rules, resulting in the emergent phenomenon of realistic flocking behaviour. Here is the footage which I remember from the documentary:

A poor historian, an adopted Northumbrian, and a frustrated web designer

Having always loved history, though having demonstrated little aptitude therefor, we moved out into rural (extremely rural) Northumberland. This is reiver country, and my brother, a fan of George MacDonald Fraser, pointed me towards Steel Bonnets, Fraser’s seminal book about the border reivers.

A serial dilettante, I was interested in computers as a child, then in print and design from around the age of seventeen. I ended up working as a web designer from the late 1990s — as a completely new discipline, my areas of interest seemed to qualify me for this line of work to some extent, though I am no great programmer, and certainly no great designer.

My first paid job at a web design agency coincided with the launch of Flash, a web animation tool. I persuaded the company to buy a copy of the software, and ended up doing work for several clients using it. This was my first real exposure to computer animation, having previously looked at traditional 3D computer animation a little while at college.

I continued using Flash over the years, as I changed jobs several times, and as Flash itself developed. In recent years, and in this current job, however, I had barely had cause to use it any more.

Reiver confluence

While walking the dog, I thought up the idea for a game which brought these various elements together: history, Northumberland, computer animation, and the web. I envisaged a game in which one had to reive cattle and sheep, which would flock realistically. Some searching online pointed me towards the work in Flash of Simon Man, who graciously allowed me to use his flocking code as the basis of Reiver. Without his work, this game would not have been made.

I got a working example up and running, but then decided that I wanted to crack another technique I had always loved, that of isometric 3D. The work of Sulake in the early 2000s influenced my interest in this visual idiom. Having attempted to achieve a similar effect at the time with a colleague, I now looked to a book we had in the office on game design in Flash. The book had an excellent section on isometric 3D in Flash, and that set me on my way.

Why game design is hard

I had a working isometric herding game, but it was very much a one-shot time-waster. I’d never really thought that this would not be enough to make a game in and of itself. I sought a lot of advice from varied sources as to how to change this one-level curiosity into a fully-fledged game — colleagues in this and other National Parks, family, and former colleagues from the private sector. Thanks throughout this endeavour are due to Steve at Presence Multimedia, former colleague at The Web Works, and Dave and Matt at Mere Mortals (at the time), formerly of Zebra and here at Northumberland National Park respectively.

In the end, one just has to think about it long enough, and something will occur, hopefully something extremely simple, and so it proved in this case. Pressure of time was added by gathering dusk, and levels were added by increasing flocks, reduced time, and larger buildings to raid.

That was MY idea!

During the later stages of development of the game, Matt told me that Red Dead Redemption had stolen my thunder. If one of the greatest games of 2010 thought that flocking behaviour and herding made a great game, then who am I to argue? That various gamers evidently hate this part of the game is of only incidental importance.